1. Field of the Invention
The invention relates to a pork product pellet which can be puffed by microwave radiation. More specifically, the invention relates to a microwavable pork skin pellet which is packaged in an expandable container. The pork pellets contained in the package may then be expanded in a microwave oven to produce a puffed pork crackling which is low in fat content and ready for human consumption.
2. Discussion of the Background
Typical Mexican food is becoming popular internationally, in particular pork cracklings. Pork cracklings are generally prepared from bacon rinds or pork skins.
Bacon rinds or pork skins have a tough leathery consistency. It is well-known that these tough pork skins can be boiled and then fried in hot oil to produce puffed pork "cracklings". The cracklings are crisp and have a mild bacon flavor. The production of pork cracklings domestically entails serious drawbacks, however, primarily due to the use of oil or butter at elevated temperatures of 200.degree. C. or higher. Fried puffed pork products are available commercially, but contain relatively high amounts of fat.
Modern consumers favor foodstuffs which have a low fat content. Low fat cooking is possible using microwave ovens which are obtaining great popularity in households all over the world. Microwave cooking is conventional and economical.
A pork rind product is described in U.S. Pat. No. 3,401,045, which is prepared by cutting pork rinds or skins into small pieces and rendering the skins at temperatures in the range from 235.degree.-255.degree. F. to harden the rinds or skins and reduce their size. The pork skins are rendered in hot oil or fat, cured in an aqueous curing or flavoring solution and then dried. The dried pieces of pork skin are then cooked in vegetable oil or shortening to puff the pork skin pieces at temperatures from about 400.degree.-425.degree. F. Such fried pork puffed products have the disadvantage that they contain large amounts of fats and oils which have been found to contribute to heart disease and atherosclerosis.
U.S. Pat. No. 2,855,309 discloses pre-treating pork rinds in an acetic acid solution to improve the puffing qualities of pork rinds. The acetic acid treated pork rinds are then fried in hot oil.
French Patent 2,501,970 teaches making a pork rind snack product by cooking pork rinds in boiling water and skimming off the resulting fats. After flavoring, the pork rinds are dried and then briefly scalded in frying oil at approximately 140.degree. C. After frying, the fried pork products are again fried at approximately 180.degree. C. to effect prolonged sealing or cooked in a microwave oven.
A puffable pork food pellet is disclosed in U.S. Pat. No. 3,725,084. The puffable pellet is prepared by forcing moisture into the spaces in the molecular structure of pork skins using steam under predetermined temperature and pressure conditions. Uniform distribution of moisture causes uniform puffing of the pork skins when the moisturized skins are cooked or French fried in fat at high temperatures.
Pork snack products are also known in which the pork rinds are further processed into a gel or slurry and then puffed by means of an extruder. U.S. Pat. No. 3,793,467 discloses a method of removing hair normally associated with commercially available pork rinds by comminuting pork rinds to a relatively small particle size, suspending and slurring the pork rinds in a liquid medium to dislodge associated hair and then separating the hair from the pork rinds. The pork rinds are then dried to a moisture content below 20% and extruded in a conventional food screw extruder in a gelatinized state in which a heated die cooks and puffs the gelatinized extrudate.
U.S. Pat. No. 4,119,742 discloses a reconstituted fried and puffed product prepared by moisturizing animal parts which are high in collagen and at least 50% of which are rendered parts. Gelatinized particles are extruded, cut into small pellets, dried and deep fat fried to produce a puffed pork product.
U.S. Pat. No. 4,262,028 discloses a puffable food composition prepared by extruding a mixture of ground animal parts and starch as a partially gelatinized mixture into a shapesustaining form. The gelatinized form is then puffed in the heated die of the extruder or by subsequent hot oil frying. An expanded textured protein product is disclosed by U.S. Pat. No. 3,662,673. The textured protein product contains oleaginous seed materials and an aqueous liquid which can be internally heated by an infrared, microwave or induction oven to expand the mixture forming an irreversibly cross-linked structure.
A package of sliced bacon which can be cooked in a microwave oven is disclosed by U.S. Pat. No. 4,786,513. The bacon slices are arranged in a stack separated by individual separating sheets and placed on an absorbent blotter to absorb liquids released during cooking. The package includes an overwrap means to allow venting of expanding gases during cooking.
Processes for preparing puffable foodstuffs are disclosed by U.S. Pat. Nos. 4,608,261 and 4,525,367. The former patent discloses a helical screw conveyor for processing a raw foodstuff in particulate form, preheating the particulate foodstuff in a preheating chamber and then subjecting the preheated food to heating by microwave energy. Moist, edible ingredients are disclosed in the latter patent which are contained in a confining structure which can be burst by pressure generated by food or gas expansion. A confining structure is also used to contain the expanded mixture after heating and rupture.
Fat fried pork products are well-known, but suffer from the disadvantage of containing substantial amounts of fats which have been implicated in serious health problems. There continues to be a need for a healthy relatively low-fat pork snack product which can be puffed by the consumer, preferably in a conventional microwave oven.
Expandable microwavable packages are used in the preparation of microwave popcorn as disclosed for example in U.S. Pat. No. 4,219,573. In order to obtain good results, it is advisable to attach to the container a segment of thermal material (susceptor) which limits the loss of heat from the corn to the bottom of the microwave oven.